<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
    <link rel="stylesheet" href="./css/index.css" />
  </head>
  <body>
    <div id="app">这是一个APP盒子</div>
    <fieldset class="f1">
      <legend>嵌套基本语法</legend>
      <div class="dv">
        <div class="dv2">dv2</div>
        <b class="bb">一个b标签</b>
        <a href="">aaaa</a>
      </div>
    </fieldset>
    <fieldset class="f2">
      <legend>嵌套基本语法-群组嵌套</legend>
      <div class="dv2">
        <div class="dv3">dv3</div>
        <b class="bb">另一个b标签</b>
        <a href="">bbbb</a>
      </div>
    </fieldset>
    <fieldset class="f3">
      <legend>多个标签嵌套一个</legend>
      <p><a href="#">p-a</a></p>
      <h1><a href="#">h1-a</a></h1>
      <div><a href="#">div-a</a></div>
    </fieldset>
    <div class="f4">一个函数</div>
  </body>
</html>
